The subject matter herein relates generally to electrical connectors having differential pairs.
With the increasing demand and complexity of modern electronic systems in high reliability applications such as military and aerospace, there is a continuing need to incorporate more electronic equipment into a confined space, while at the same time ensuring reliability in harsh environments. In such applications, connector systems provide a critical communication link between physically separated electronic devices. Connector systems have to satisfy many competing requirements. For example, electrical connectors may need to be capable of withstanding a rugged environment that includes vibration, wide temperature swings, moisture, and exposure to hazardous materials and chemical contaminants. Electrical connectors may need to be compact to permit many interconnections to be made within a small area and include a small number of individual pieces. Electrical connectors may need to have high quality electrical characteristics, with matched impedance, very low signal loss, and minimal crosstalk. Electrical connectors may need to be field repairable with individual contacts being replaceable so as to not have to replace the entire electrical connector.
High reliability connector systems are often used to facilitate 100Base T, 1000Base T and 10 GBase T Ethernet applications such as those found in commercial avionics systems. Additional applications, for example, include aircraft data networks, in-flight entertainment systems (IFE) and other mil-aero networking applications where Gigabit Ethernet IEEE 802.3, Fiber Channel XT11.2, 1394, USB, 1553, Fiber Channel, VME, Can-Buss, J1708 or other multi-gigabit connectivity architecture is required. In such communication networks in which it is desirable to transfer data at high speeds over distances up to one-hundred meters, it is known to use balanced matched impedance copper cabling. The copper cables are connected to the various interfaces in a communications network using plug-in modular electrical connectors. A conventional cable used to transfer data includes an insulating cable sheath that contains pairs of copper wires. The pairs of wires are twisted together in order to reduce crosstalk. The Ethernet protocol uses four pairs per channel, and each pair needs to be shielded from the other pairs to preclude cross-talk between the pairs. Furthermore, when the channel is used in a full duplex manner, i.e., to support simultaneous bidirectional communications, it is also necessary to prevent disturbance by near end crosstalk and far end crosstalk from the other pairs. Thus, in a given Ethernet channel, there are six disturbing sources per pair. Consequently, both the position of the wires and the components of the modular connector all play a role in preventing signal degradation.
A need remains for an improved matched-impedance, shielded-pair interconnection system for high speed data transmission for harsh operating environments that may be packaged in a minimal form factor.